This invention relates to the field of microwave food packaging, and more particularly to the control of heating using a conductive member such as a metal foil in microwave food packaging.
Controlled heating of food in microwaves is very important to insure the proper cooking conditions. Such cooking conditions may require uniform heating of food, the avoidance of heating in certain areas or the deliberate heating of food in others. To insure that these various conditions are met, the use of metal foils has been known in microwave food packaging. Use of foil has included promoting even and more intense heating of food and isolating portions of the food from excessive heating. It is also known that use of metal foil in microwave ovens includes the risks of excessive heating or arcing. However, what is not known is the crucial role the profile of the foil edge, and the smoothness of the opening formed by the edge, play in these risks. The present invention advances the art by providing a method for designing the edge geometry to remain within acceptable levels of risk of overheating and arcing.